Grinding mill

ABSTRACT

The grinding mill includes a chamber having a rolling track and a base beneath the track. A plate within the base carries a roller engaging the track, and reduction gearing secured to the base rotate the plate. The output shaft of the gear is connected directly to the plate. An air duct carries compressed air to a passage defined by an annular shoulder depending from the plate. An opening in the base admits air required for grinding.

United States Patent [191 Desbordes Jan. 15, 1974 GRINDING MILL 3,093,327 6/1963 Harvey et al. 241/47 x [75] n n Jean esbo des, aris rance 335,574 2/1886 Fuller et al. 241/57 [73] Assignee: $3 g l g Stein Primary Examiner-Granville Y. Custer, Jr.

n us rance Att0rney--Breitenfeld & Levine [22] Filed: Dec. 8, 1969 [21] Appl. No.2 883,078 r [57] ABSTRACT [30] Foreign Application Priority Data The grinding mill includes a chamber having a rolling Dec 9 [968 France 68 H718 track and a base beneath the track. A plate within the base carries a roller engaging the track, and reduction gearing secured to the base rotate the plate. The out- (g1. put shaft of the gear is connected directly to the plate. An air duct carries compressed air to a passage [58] Fleld of Search 241/47, 57, 62 fined y an annular Shoulder depending from the 56] References Cited plate. An opening in the base admits air required for d UNITED STATES PATENTS gm mg 1,781,572 11/1930 Drummond 241/47 3 Claims, 1 Drawing Figure PATENTEBJAN 1 5 .974

l/v VEN rug:

1 E: UOHDES JEAN GRINDING MILL This invention relates to a grinding mill equipped with rollers carried by a rotary plate located at the bottom of the said grinding mill and adapted to cooperate, under the action of centrifugal force, with a rolling path situated at a higher level than that of the plate.

Driving of the plate in rotation is effected by a vertical shaft extending below the said plate and driven from a horizontal driving shaft through the intermediary of suitable reduction gearing.

The applicant has found that it is possible to increase the simplicity and lightness of the apparatus by equipping the grinding mill with reduction gearing of conventional type, preferably a .commercial reduction gearing, and coupling the roller-carrying plate directly to the output shaft of the reduction gearing. In this manner the output shaft of the reduction gearing serves also as the driving shaft of the plate, and the radial and axial bearings of the reduction gearing are utilized for both supporting and rotating the plate. It will be understood from this that the apparatus will be lighter and that in the event of wear or damage of the bearings it is sufficient to uncouple the plate from the output shaft of the reduction gearing and to perform a standard exchange of the reduction gearing.

Further, in accordance with another feature of the present invention there is provided, through the reduction gearing, a supply duct for air under pressure intended to prevent dust in the interior of the grinding mill from reaching the shaft of the reduction gearing and penetrating into it. For this purpose the air, at a suitable pressure relative to the pressure obtaining in the grinding mill, is fed to the vicinity of the output shaft of the reduction gearing, under the plate into a passage formed as an annular duct resulting from a suitable shoulder provided on the lower face of the plate.

Other features also forming part of the invention will appear from the description that follows of the single FIGURE of the accompanying drawing, which is given byway of example and which shows diagrammatically,

in vertical section, a grinding mill improved in accordance with the present invention. 1

In the drawing, 1 indicates the chamber of circular section of a grinding mill the base la of which has an inlet 23 for the introduction of theair required for the grinding operation. In contrast to the majority of grinding mills with pendular bodies, in which the air enters a chamber in which the air is distributed by means of fixed blades, here the entry of air takes place directly without blading, which increases the simplicity and lightness of the apparatus.

The lower part of the chamber 1 supports a fixed rolling track 4 of high resistance steel.

The rollers 11, which are adapted to be applied by centrifugal force to the rolling track 4, are carried by a plate 10 situated at the lower part of the base In. In the embodiment illustrated each roller 11 is movable around an axis one end of which is solid with a stirrup 14 which can swing about pivots such as 15 carried by the plate 10. Further, blades 18 or any other device adapted to throw the coarse product on to the rolling track of the rollers, may be solid with the plate 10.

The plate 10 carrying the pendular bodies is made solid with the shaft 24 by keying or any other suitable means. In the example illustrated is is made solid with the shaft by a conical sleeve 26.

The vertical output shaft 24 is journalled in bearings such as 27 and 27', the latter forming thrust bearings, and carries a gear wheel 28 engaged with a pinion 29 solid with a secondary shaft 30 which also carries a bevel gear 31. The latter is engaged with a bevel pinion 32 carried by the input shaft 33 of the reduction gearing, which is driven in rotation by a suitable motor.

Further, through the reduction gearing 25 there is provided an air duct 34 which opens at 35 beneath the plate 10 and in the vicinity of the shaft 24. This air, at a suitable pressure relative to the pressure obtaining in the grinding mill owing to the introduction of grinding air through the opening 23, passes into an annular passage formed by an annular shoulder 36 on the lower face of the plate 10. This circulation of air prevents dust from reaching the shaft 24 and penetrating into the reduction gearing 25.

What is claimed is:

l. A grinding mil] comprising a housing defining a grinding chamber with a bottom base, a rotatable plate located immediately above the bottom base in said chamber, a rolling track fixed in said housing at a level above said plate, at least one roller pivotably supported on said plate for traveling along said track as the plate rotates, a source of rotary power for said plate, and reduction gearing between said power source and said plate, said gearing being secured to said bottom base and the output shaft of said gearing being coupled directly to said plate.

2. A grinding mill as defined in claim 1, including an annular shoulder projecting downwardly from the lower face of said plate, and a duct for air under pressure, said duct passing through said reduction gearing and opening in the vicinity of said gearing output shaft beneath said plate, into a passage formed by said shoulder.

3. A grinding mill as defined in claim 1 wherein said base is located beneath said rolling track, and said base has an opening for the admission of air. 

1. A grinding mill comprising a housing defining a grinding chamber with a bottom base, a rotatable plate located immediately above the bottom base in said chamber, a rolling track fixed in said housing at a level above said plate, at least one roller pivotably supported on said plate for traveling along said track as the plate rotates, a source of rotary power for said plate, and reduction gearing between said power source and said plate, said gearing being secured to said bottom base and the output shaft of said gearing being coupled directly to said plate.
 2. A grinding mill as defined in claim 1, including an annular shoulder projecting downwardly from the lower face of said plate, and a duct for air under pressure, said duct passing through said reduction gearing and opening in the vicinity of said gearing output shaft beneath said plate, into a passage formed by said shoulder.
 3. A grinding mill as defined in claim 1 wherein said base is located beneath said rolling track, and said base has an opening for the admission of air. 